Tube Preamps.....

Another vote for the Freya. At least give it a try. For $700 bucks with a 15 day return less 5% restocking fee (and shipping) you will risk little.   It’s a very flexible, balanced design with (tiny) remote, several output modes (one of which is 6SN7 tube-based) and numerous inputs. Also has a very very good volume control and 5 year warranty.
I know...it doesn't cost enough so it must be junk. Why not let your ears decide?  

You could do Freya + Gungnir MB or even the Yggdrasil DAC at your (stretch) budget. Lots more info over on HeadFi (Freya impressions and tube rolling thread). Good luck.

http://www.schiit.com/products/freya

https://www.head-fi.org/threads/schiit-freya-impressions-and-tube-rolling-thread.832177/

Note that the only serious issue with a Freya is the fact that you could become obsessed with 6SN7 tube types…my SE power amp also has one of these (a NOS Amperex), so I seem to now have a tube collecting problem with the Freya original 6N8S tubes (which are possibly all you need), Sylvania "chrome domes," more NOS Amperex when I can find them, new version Tung Sols (not too shabby really), and more coming from stashes of NOS RCAs and on it goes. You've been warned.

If you can live without a remote, I recommend the CJ Classic tube preamp. Used ones show up on Agon all along with very attractive pricing. I’ve owned PrimaLuna and I consider this a (significant) upgrade. 

I second the Denafrips DAC. For preamps, I’ve had a half dozen or so, but a few years ago bought a demo Rogue Metis Magnum for only $1100 (didn’t even listen to the stock tubes initially) and being new to tube preamps paired w solid state amps, over a year and a half stretch of obsession, rolled about $4k worth of 6SN7 and VT99 tubes (w adapters). I ultimately declared a clear winner.. and that was the NOS (or even used) VT-99 Tung Sol’s (also black glass like their 6SN7 brothers). In the VT-99, flat plate or round plate.. both are suprisingly similar, they were dramatically quieter, higher bandwidth, and therefore more revealing than anything else. Raytheon’s and Sylvania grey glass (from Argentina) were also excellent but a step back from TS VT99. Even Tung Sol’s crazy expensive much heralded round plate 6SN7 didn’t come close.. too noisy and twice and expensive. On a lark one day, i put in the original tubes (still low hrs) and they were unlistenable, relatively speaking. I’m not sure how the preamp garnered such rave reviews with them, but perhaps i’d just been spoiled . I believe the Metis loves great NOS VT-99’s w adapters because it separates the main power lead from the interior of the Tube, which is important in a lower tier preamp such as the Metis. Expensive tube preamps are probably less sensitive to rolling, but this one needs the separated lead to operate quietly. Here, It is a very dynamic, transparent preamp which injects the perfect amount of 2nd harmonic distortion into my solid state equipment chain. So you’re looking at maybe $1200-1400 (w NOS tubes and adapters) for a giant killer.